1. Field of the Invention
The present invention relates to precursor compositions having utility for atomic layer deposition and chemical vapor deposition of titanate, lanthanate, and tantalate thin films, e.g., in the manufacture of microelectronic devices, as well as to processes of making and using such precursors, to products formed using such precursor compositions, and to precursor supply systems comprising such precursor compositions in packaged form.
2. Description of the Related Art
Strontium titanate (SrTiO3), barium titanate (BaTiO3) and barium strontium titanates (BaxSr1-xTiO3 where 0≦x≦1) are high dielectric constant materials that are potentially useful in future generation flash memories as well as other microelectronic products. Lanthanum oxides (La2O3), lanthanum tantalates (LaxTayOz where x, y, and z denote oxides of varying composition), and lanthanum titanates (e.g. LaTiO3) represent another class of high dielectric constant materials potentially useful on future generation microelectronic devices. Uniform coating involving greater than 90% step coverage on high aspect ratio structures is required for such titanate materials to achieve requisite high capacity in flash memory device applications.
Atomic layer deposition (ALD) is currently being explored as a technique for achieving such step coverage, using strontium β-diketonates and titanium β-diketonates as precursors. It is difficult, however, to achieve satisfactory uniform coating of strontium titanate thin films using the β-diketonate precursors that have been developed to date. Similar deficiencies are encountered when chemical vapor deposition (CVD) is used as a deposition technique to form such titanate films.
The art continues to seek new precursors for deposition of thin film titanates, lanthanates and tantalates such as strontium titanate, barium titanate, barium strontium titanate, lanthanum oxide, lanthanum tantalate, and lanthanum titanate.